New horizons in life extension, healthspan extension and exceptional longevity.

Many common chronic diseases and syndromes are ageing-related. This raises the prospect that therapeutic agents that target the biological changes of ageing will prevent or delay multiple diseases with a single therapy. Gerotherapeutic drugs are those that target pathways involved in ageing, with the aims of reducing the burden of ageing-related diseases and increasing lifespan and healthspan. The approach to discovering gerotherapeutic drugs is similar to that used to discover drugs for diseases. This includes screening for novel compounds that act on receptors or pathways that influence ageing or repurposing of drugs currently available for other indications. A novel approach involves studying populations with exceptional longevity, in order to identify genes variants linked with longer lifespan and could be targeted by drugs. Metformin, rapamycin and precursors of nicotinamide adenine dinucleotide are amongst the frontrunners of gerotherapeutics that are moving into human clinical trials to evaluate their effects on ageing. There are also increasing numbers of potential gerotherapeutic drugs in the pipeline or being studied in animal models. A key hurdle is designing clinical trials that are both feasible and can provide sufficient clinical evidence to support licencing and marketing of gerotherapeutic drugs.